Method of patterning metal surfaces



April 12, 1966 J. B. LLOYD-LUCAS 3,245,851

D R I Filed Oct. 16. 1961 2 Sheets-Sheet 1 April 12, 1966 .1. B. LLOYDLUCAS 3,245,351

METHOD OF PATTERNING METAL SURFACES Filed Oct. 16. 1961 2 Sheets-Sheet 2 United States Patent 3,245 851 METHOD OF PATTERNIlIG METAL SURFACES John Brian Lloyd-Lucas, Solihull, England, assignor to Mark Perks Limited, Birmingham, Engiand, a British company Filed Oct. 16, 1961, Ser. No. 145,175 Claims priority, application Great Britain, Oct. 17, 1960, 35,551/ 60 4 Claims. (Cl. 156-7) This invention relates to the patterning of metal surfaces.

In accordance with the invention there is provided a process for the patterning of a metal surface, wherein the metal surface has applied directly thereto, under pressure, a patterning die having an impression surface of which portions in relief are roughened, serrated, engraved, engine-turned or otherwise abraded, the die being pressed onto said metal surface to form an impression in which the patterning effect is defined by the contrast of a matt or other serrated area produced by the die, against the remaining polished or other treated are-a of the metal surface.

The die, which may be of steel, beryllium copper or other metal, may be treated by chemical action, engraving, milling or engine-turning, or other processes, in the formation of the impression surface. The impression surface may be further abraded or patterned as by shot-blasting, sand-blasting, scratch-brushing, polishing or other operations. The impression surface may alternatively or, in addition, be electroctched or ele-ctro-polished, wholly or in parts, or engraved to include letters, names or other ciphers, either in relief or in intagl-io. The die may be hardened or reinforced according to the surface to be processed.

For a better understanding of the invention and the method by which it is to be performed, examples thereof will now be described, reference being made to the accompanying diagrammatic drawings, in which:

FIGURE 1 is a fragmentary perspective view of apparatus for carrying out an example of the process,

FIGURE 2 is an exploded sectional view taken along the line II-II of FIGURE 1, showing parts in an initial stage of the process,

FIGURE 3 is a sectional view similar to that of FIG- URE 2 but showing the parts in a subsequent stage of the process,

FIGURE 4 is a perspective view of a tool part shown in FIGURE 1,

FIGURE 5 is an enlarged detail of FIGURE 4, and

FIGURE 6 is a fragmentary plan view illustrating a pattern formed with the apparatus shown in FIGURES l to 5.

Referring to FIGURE 1 of the drawings, the apparatus exemplified for carrying out the process, comprises a rolling mill having upper and lower rolls 1, 2 rotatably mounted in end-frame members 3, 4, there being screw-adjusters 5, 6 to permit adjustment in the spacing of the roll-s 1, 2 according to the nature of the work. In the present arrangement, individual power operated drive means is provided for rotating the rolls 1, 2 in counter directions. The apparatus comprises also a feed table 7 extending upwardly towards the nip between the rolls, for guiding the work assembly, indicated generally at 8, to the rolls. The apparatus further comprises, at the opposite side of the rolls, a delivery table 9. The operation of the apparatus will be further described in the following examples of the process:

Example 1 This example is concerned with the patterning of a pretreated surface of a strip 10 of sheet aluminium which is of about 0.100 inch in thickness. The surface to be patterned is, in the present example, pretreated by being highly polished. The workpiece is arranged so that its polished or treated surface is directed downwardly, the sheet being supported upon a die 11. On top of the sheet 10 there is placed a planishing piece 12. The work assembly 8 to be passed between the rolls is thus of sandwich formation.

The planishin-g piece 12 is formed of metal plate of about /2 inch in thickness. In the present embodiment, the die 11 is of mild steel about 1 inch in thickness and measuring approximately 3 inches in width and 12 inches in length. The die 11 has an upper impression surface 13 in which there are formed a number of equi-spaced transverse grooves or channels 14 which are about inch in width and depth, and which define in relief, the raised lands or strip-like areas 15. These areas 15 are roughened by being subjected to a shot-blasting operation. The engraving of the impression surface of the die 11, to form the grooves 14 is effected mechanically by a milling operation. It will, however, be understood that the grooves could be formed as by etching or other shaping processes. In the present example, the grooves 14 are greater in depth than the depth of the impression of the pattern to be formed in the metal surface of the workpiece 10. The abrading or r-oughening of the raised impression face or faces of the die could alternatively be effected by etching, sand-blasting or other mechanical means. The die 11 may be hardened or case hardened. The whole of the impression surface of the die, or merely the raised areas 15 thereof, may be subjected to the shot-blasting or like operation.

The die 11 is formed also in its impression surface with parts recessed to approximately the same depth as the grooves 14 and arranged to define letters or ciphers as shown at 16 in FIGURE 4.

With the sheet metal workpiece 10 sandwiched between the die plate 11 and the superposed planishing piece 12, the work assembly is guided by the inclined table 7 towards and into the nip between the rolls 1, 2. The screwadjusters 5, 6 are so adjusted that the pressure .applied by the rolls 1, 2 is sufiicient, as the work assembly passes between the rolls, to cause an impression of the raised abraded areas 15 of the die 11 to be formed in the polished surface of the metal sheet 10 without, however, forcing the die into the metal sheet to the full depth of the grooves 14 of the impression surface. In this manner, the raised abraded .areas 15 of the impression surface contact and are pressed into the polished metal surface of the sheet 10 so as to produce thereon a patterned effect which, as illustrated diagrammatically in FIGURE 6, is defined by recessed matt areas 17, corresponding to the raised.

Example 2 In this example, the patterning process is carried out as already described in Example 1, the sheet aluminium workpiece of Example 1 being replaced by one of sheet brass which has been nickel-plated and then chromium plated. As the nickel and chromium-plated brass workpiece is passed together with the die 11 and planishing piece 12, between the rollers 1, 2, the roughened raised areas 15 of the die perform an abrading operation in which they break down the corresponding portions of the metal plated surface of the workpiece to form patterns contrasted against those portions of the work piece which correspond to the grooves 14 of the die and which remain bright and unaffected by the abrading or roughening action performed by the raised areas 15 of the die. If desired, the sheet metal workpiece may be formed of a metal other than brass and similarly plated with nickel, chromium or other metal coatings.

Example 3 In this example a chromium plated brass workpiece has a pattern applied thereto in the manner described in Example 2. Thereafter, the workpiece is placed in a bath of corrosive liquid which penetrates the broken chromeplated surface but which does not attack the bright chrome-plated areas of the patterned surface, i.e., those areas corresponding to the grooves or recessed portions of the die. The corrosive liquid consists of a dilute solution, for example a solution, of sulphuric acid. The workpiece is left in the solution until the etching has penetrated the broken chrome surface to a suflicient depth. When the workpiece is removed from the corrosive liquid, the patterns formed by the broken chrome-plated areas appear as etched brass surfaces or areas against the unbroken areas of the chrome-plated surface.

The etched and patterned surface of the workpiece may thereafter be repolished slightly and gilded by conventional methods. In the gilding operation, the gold from the gilding solution adheres to the brass parts but not to the chromium-plated parts, this imparting a further decorative patterning effect to the surface of the workpiece. If desired, the gold of the gilding solution may be replaced by other colouring products, for example, copper, bronze or other coating solutions.

If desired, a workpiece of sheet aluminium may first be anodized before being rolled and the surface thereof abraded as in Example 1. This provides a decorative effect in the patterned surface and the latter surface may be reanodized after the rolling operation, to maintain the bright and matt parts of the anodized surface. If desired, the reanodizing operation may be performed in a different colour to produce contrasting effects in the final pattern. The process may further be modified by subjecting the workpiece, after the rolling operation, to the corrosive action of a caustic solution on the abraded parts of the patterned surface, the latter thereafter being reanodized in a colour.

A third or further colour may be introduced into the patterning of the surface of the workpiece, by treating the previously patterned surface with a varnish or other resistant coating, the treated surface then being subjected to a further rolling operation with a third patterning die so that the varnish or other resistant coating will be abraded in a manner similar to that involved in the abrading of the chromium-plated workpiece as described in Example 3. Thus, the varnish or other resistant coating will be broken down in desired areas as determined 'by the third patterning die, the workpiece thereafter being replated or anodized to apply a third contrasting colour to the patterned surface.

It will be understood that other desired combinations of the strips of metal plating, etching with corrosive liquids, and resistant coating, may be employed in. the patterning of a metal surface.

In accordance with a further modification of the process, a metal-plated or anodized surface of a metal workpiece, may be treated or abraded so as to break down the plated or anodized surface in predetermined areas to dissolve or remove the abraded surface and to recolour, plate or anodize such abraded surface to impose thereon a fresh texture and/ or colour.

A decorative effect can be obtained not only by the use of dies treated with patterning media such as fine chemical etching, scratch-brushing, coarse lining or engineturning, engraving, or milling, but further decorative or patterning effects can be produced by the use of materials such as wire mesh, cotton fabrics, nylon fabrics, grained wood or the like.

Use can be made of wire mesh, pierced metal, or other material or mechanical cutting means in the breaking down or penetration of the metal-plated, anodized or other coated surface of the workpiece.

The impression face of the die may be abraded as by sand-blasting, shot-blasting or other means, to such a depth that, when the die is pressed onto a chrome-plated sheet, the abraded areas in relief of the die will, in the areas of contact with the plated sheet, destroy the adhesion of, or pierce, the chrome plating. In this manner, a more pronounced patterning effect is obtained. This can be accentuated by immersing the metal sheet, after being impressed with the pattern, in a bath of corrosive treatment liquid comprising, in the case of a brass plate, an acid solution. Where the metal plate is of aluminium, the treatment liquid may consist of an alkali solution or phosphoric acid. The treatment liquid seeps into the cracked or pierced avenues of the chrome plating, thereby lifting parts of the plating in the patterned areas, while leaving substantially unaffected the remaining areas of the plated surface. In this manner, a multi-toned patterning effect is obtained in which the metal surface includes unmarked chrome-plated areas and serrated plated areas including portions of eroded or etched brass. The patterned surface may thereafter be plated in such a manner that the plating will adhere to the eroded areas of the brass but not to the chromium plated areas. Alternatively, the brass areas may be coloured by oxidising or bronzing methods. The metal plate may then have a protective coating of lacquer applied thereto.

A mult-i-toned pattern may similarly be applied to the surface of an aluminium sheet. For example, the aluminium surface may be dyed, fully anodized and lacquered, the treated surface thereafter being subjected to the impression surface of the die plate or matrix, in a manner similar to that already described with respect to the chromium-plated brass sheet. The anodized and lacquered film of the aluminium sheet is thus crushed or serrated in the patterned areas, and here again the marked areas may be accentuated by immersing the sheet for a short time in a treatment bath containing a dilute alkali solution. The unmarked areas of the dyed and lacquered film remain substantially unaffected by the treatment solution, whereas in the marked areas the solution will produce a degree of erosion of the aluminium surface.

The eroded surface can be dyed, thus producing a two-colour effect. The whole is then resprayed with lacquer or suitable stop-off solution and a further pattern impressed in a similar manner, producing an additional crushed pattern, which in turn may be dyed another colour.

It will be understood that the process may be employed to render chromium plated surfaces porous for lubrication purposes.

What is claimed is:

1. A process for the patterning of a metal surface of a sheet metal workpiece, said process including the steps of applying a metal coating to said metal surface, applying said coated surface directly to an impression surface of a patterning die, said impression surface having portions in relief to define raised patterning areas of roughened configuration, applying to the other surface of said workpiece remote from said coated surface, a planishing piece so that the workpiece is interposed between said patterning die and said planishing piece to form a work assembly, in which said workpiece is disposed between said die and said planishing piece with said metal surface of the workpiece bearing directly against the impression surface of said die, and said other surface of the workpiece is in direct contact with but capable of displacement relatively to the planis-hing piece, passing the assembly between cooperating rolls of a rolling mill and apply ng pressure to the assembly so as by a metal deforming ope-ration to reduce the thickness of parts of the workpiece and to cause other parts of the coated metal surface of said workpiece to penetrate the impression surface of the die to a depth less than the depth of the raised patterning areas of said impression surface, and to break down the coated surface of said workpiece in areas corresponding to the raised patterning areas of the impression surface of said die, said other surface of the workpiece being maintained substantially smooth by contact with said planishing piece, removing the workpiece from between said impression die and said planishing piece, after the metal deforming operation, and then applying an etching solution to the coated surface of said workpiece to eifect an etching of the metal in those areas where the coating of the workpiece has been broken down by the impression surface of said die.

2. A process according to claim 1 wherein the base metal is aluminum and the coating is colored anodized aluminum.

3. A process according to claim 1 wherein the opposite sides of the base are similarly treated.

4. A process according to claim 2 wherein the opposite sides of the base are similarly treated.

References Cited by the Examiner UNITED STATES PATENTS 1,656,928 1/ 1928 Wheeler.

1,722,778 7/ 1928 Wheeler.

1,821,578 9/1931 Povalski 402.2 X 1,846,171 2/1932 Wheeler 41-18 X 2,632,69 3/ 1953 Jenkins 156-6 2,662,002 12/ 1953 Sunderhauf et a1.

2,691,627 10/ 1954 Johnson 204-18 2,988,838 6/1961 Morgan 10132 3,054,709 9/ 1962 'Freestone et al 1566 FOREIGN PATENTS 559,471 6/ 1958 Canada.

ALEXANDER WYMAN, Primary Examiner.

JACOB STEINBERG, EARL M. BERGERT, W. A.

POWELL, Examiners. 

1. A PROCESS FOR THE PATTERNING OF A METAL SURFACE OF A SHEET METAL WORKPIECE, SAID PROCESS INCLUDING THE STEPS OF APPLYING A METAL COATING TO SAID METAL SURFACE, APPLYING SAID COATED SURFACE DIRECTLY TO AN IMPRESSION SURFACE OF A PATTERNING DIE, SAID IMPRESSION SURFACE HAVING PORTIONS IN RELIEF TO DEFINE RAISED PATTERNING AREAS OF ROUGHENED CONFIGURATION, APPLYING TO THE OTHER SURFACE OF SAID WORKPIECE REMOTE FROM SAID COATED SURFACE, A PLANISHING PIECE SO THAT THE WORKPIECE IS INTERPOSED BETWEEN SAID PATTERNING DIE AND SAID PLANISHING PIECE TO FORM A WORK ASSEMBLY, IN WHICH SAID WORKPIECE IS DISPOSED BETWEEN SAID DIE AND SAID PLANISHING PIECE WITH SAID METAL SURFACE OF THE WORKPIECE BEARING DIRECTLY AGAINST THE IMPRESSION SURFACE OF SAID DIE, AND SAID OTHER SURFACE OF THE WORKPIECE IS IN DIRECT CONTACT WITH BUT CAPABLE OF DISPLACEMENT RELATIVELY TO THE PLANISHING PIECE, PASSING THE ASSEMBLY BETWEEN COOPERATING ROLLS OF A ROLLING MILL AND APPLYING PRESSURE TO THE ASSEMBLY SO AS BY A METAL DEFORMING OPERATION TO REDUCE THE THICKNESS OF PARTS OF THE WORKPIECE AND TO CAUSE OTHER PARTS OF THE COATED METAL SURFACE OF SAID WORKPIECE TO PENETRATE THE IMPRESSION SURFACE OF THE DIE TO A DEPTH LESS THAN THE DEPTH OF THE RAISED PATTERNING AREAS OF SAID IMPRESSION SURFACE, AND TO BREAK DOWN THE COATED SURFACE OF SAID WORKPIECE IN AREAS CORRESPONDING TO THE RAISED PATTERNING AREAS OF THE IMPRESSION SURFACE OF SAID DIE, SAID OTHER SURFACE OF THE WORKPIECE BEING MAINTAINED SUBSTANTIALLY SMOOTH BY CONTACT WITH SAID PLANISHING PIECE, REMOVING THE WORKPIECE FROM BETWEEN SAID IMPRESSION DIE AND SAID PLANISHING PIECE, AFTER THE METAL DEFORMING OPERATION, AND THEN APPLYING AN ETCHING SOLUTION TO THE COATED SURFACE OF SAID WORKPIECE TO EFFECT AN ETCHING OF THE METAL IN THOSE AREAS WHERE THE COATING OF THE WORKPIECE HAS BEEN BROKEN DOWN BY THE IMPRESSION SURFACE OF SAID DIE. 